<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<div id="app">
  <h2>总价格 : {{totalPrice}}</h2>
</div>

<script src="./js/vue.js"></script>

<script>
  const app = new Vue({
    el:'#app',
    data:{
        message:'Hello World',
        books:[
            {id:110, name:'Unix编程艺术', price: 119},
            {id:111, name:'代码大全', price: 105},
            {id:112, name:'深入理解计算机组成原理', price: 98},
            {id:113, name:'现代操作系统', price: 87}
        ]
    },
    computed:{
        totalPrice:function(){
          let result = 0 ;
          for(let book of this.books){
              result += book.price;
          }
          return result;
        }
    }
  });
</script>
</body>
</html>